1. Field of the Invention
The present invention relates generally to power chucks, and more particularly to, a power chuck providing a substantially constant power ratio.
2. Description of the Related Art
Generally, power chucks are used to hold a workpiece. Typically, these power chucks are mounted on a rotatable spindle of a machine tool. Commonly, the power chuck has a body and an axially disposed actuator mounted for reciprocation therein. The power chuck also has a plurality of axially extending rocker arms with work engaging jaws spaced radially equidistantly around the actuator and mounted for rocking movement to engage and disengage the workpiece.
One problem with these types of power chucks is that the actuator does not provide constant power to the rocker arms. Another problem is that only partial contact exists between the ball of the rocker arm and the swivel mounting, resulting in less accuracy in gripping the workpiece. Yet another problem is that the work engaging jaws cannot be removed quickly from the rocker arms.